Submitted to Marine Resource Management Program College of Earth, Oceanic, and Atmospheric Sciences Oregon State University Corvallis, Oregon 97331 2012 In partial fulfillment of the requirements for the degree of

I understand that my project will become part of the permanent collection of Oregon State University Libraries. My signature below authorizes the release of my project paper to any reader upon request.

Baiq H. Astriana, Author

Anna. gave me great support. all MRMers and CEOAS people who have been so nice. Without their help. and my fiancé for supporting me throughout my study at Oregon State University. and George Waldbusser. friendlier. my family. One simply could not wish for better. and Robert Allan as committee members. I also want to thank Lori. helpful. Finally. as my major adviser.iv
ACKNOWLEDGEMENT
I offer my sincerest gratitude to Flaxen Conway. provided most of information I needed. and awesome adviser and committee members. I want to attribute the level of my Master degree to their encouragement and effort. I thank my parents. They patiently led me to this project. this paper would not have been completed. and allowed me to have the room to work on my way. and best friends for me.
.

it has been known that effluent from shrimp farms (particularly the intensive one) consists of accumulated nutrients (such as nitrogen) discharged to the sea and can degrade sea water quality. This project determines the possibility of using IMTA to improve shrimp farms in NTB. and increases understanding of nitrogen dynamics in IMTA system using a mechanistic model. Ministry of Marine and Fisheries Affair of Republic of Indonesia recently issued General Guideline for “Minapolitan” (fisheries city) Development. It contributes to 8. a concept of economic development of maritime affairs and fisheries region in which intensification of shrimp farms is one of the directions. particularly shrimp farm practices. Data and conceptual models for modeling purpose were adopted and combined from relevant studies. helps to document negative impacts of intensive shrimp farms. Recommendations and illustrations about nitrogen dynamics provided in this paper are expected to motivate the NTB government to monitor “minapolitan” development . Integrated Multitrophic Aquaculture (IMTA) is known as a strategy used for reducing waste from shrimp farms using biofilters. Indonesia
ABSTRACT
In Nusa Tenggara Barat (NTB).) and Seaweed (Gracilaria sp. However. produces a recommendation for the government.v
Evaluation of the Potential of Integrated Multi-trophic Aquaculture (IMTA) using Oyster (Crassostrea sp.) for Shrimp (Penaeus monodon) Farms to Reduce Negative Impacts on Environment and to Improve Coastal Economy in Nusa Tenggara Barat. In order to improve aquaculture practices including shrimp farms. Indonesia.74% of total Indonesian shrimp production value. and to promote IMTA implementation so that the sustainability of marine ecosystem services could be pursued in the short-term and in the long-term.
. shrimp is one of the most produced seafood.

2 Table 2.4 Table 2.6 Table 3.1 Table 2.5 Export shrimp and prawns frozen of Indonesia Production of shrimp of NTB and Indonesia in 2009 The Value of Shrimp Production of NTB and Indonesia in 2009 The value of seaweed production in NTB 2009 (in Rupiahs) Indonesian Export of Seaweed during a Decade Export of Oyster Fit for Human Consumption of Indonesia Parameters in IMTA ponds designed Parameters in governing equations used to model nitrogen dynamic in Penaeus monodon pond Parameters in governing equations used to model nitrogen dynamic in Crassostrea sp. quantified as the median daily percent difference between the standard and sensitivity model runs across all spatial elements.3 Table 3. pond Parameters in governing equations used to model nitrogen dynamic in Crassostrea sp.2 Table 3.4 Table 3. Results are listed only for parameters and state variables when differences were ≥ 10% Page 11 11 12 13 13 14 32 34 36 42 43
.5 Table 2.viii
LIST OF TABLES Table Table 2.1 Table 3.3 Table 2. Pond Sensitivity of modeled Gracilaria area-weighted biomass to parameters and intial conditions.

2 Figure 2.2 Map of Indonesia and NTB province An example of effluent produced by one of shrimp farms in Sumbawa Regency. NTB Location of Minapolitan Areas for Seaweed in Province of NTB Simple concept of IMTA system (shrimp with oyster and seaweed) The conceptual model we created for determining nitrogen dynamics in IMTA design in NTB (built with three existing conceptual models from other places) Page 3 4 19 30 31
.1 Figure 3.ix
LIST OF FIGURES Figure Figure 1.1 Figure 1.1 Figure 3.

Fishery products from aquaculture have supplied more than 50% of world’s consumption of seafood (Conservation International. Indonesia has an abundant amount of marine resources (Figure 1. 2011).
As an archipelago country. and Integrated Multi-trophic Aquaculture (IMTA) The increase of demand on fishery products. which include the provincial
. has led to ecosystem degradation in marine and coastal areas through activities such as overfishing and destructive fishing. especially capture fish. Ministry of Marine and Fisheries Affair of Republic of Indonesia made a regulation called General Guideline for Minapolitan Development (Minapolitan).
In order to deal with this situation. Data show that the number of poor people living in this particular area is about 3. This guideline was forwarded and assigned to provincial governments.1). However.284 million (Riyono. The success of land-based aquaculture in improving fishery production and the quality of product has caused this practice to rapidly grow. This was issued in 2009 followed by two other regulations in 2010 and 2011. By looking at this condition. this condition does not seem to support people’s lives.
Land-based aquaculture seems to offer a sustainable fishery without overexploiting marine resources. The situation is getting worse when human demand on seafood does not offset the capacity of marine ecosystem in providing this service.1
CHAPTER 1
INTRODUCTION: Tendency of Aquaculture Development. Minapolitan. 2011). There are good tendencies shown by aquaculture practices in many countries. particularly those living in coastal areas. it can be predicted that more aquaculture practice will be done in the future.

The impact of water effluent discharged from shrimp ponds to the sea (Figure 1. the regulation that controls Minapolitan does not have any point that is aimed to maintain ecosystem health (concerned only with economic improvement).
. feeding ground. phosphorus.
However. 2006). Minapolitan.2) has triggered reaction from community around the land-based aquaculture.74% of total Indonesian shrimp production value (Central Statistical Agency Republic of Indonesia. issues about seawater pollution have been recognized. it has been known that aquaculture practice tend to cause some new problems. In order to develop ponds. aquaculture. Water effluent (consists of accumulation of nitrogen.) from this activity is discharged to the sea and degrades the seawater quality (Shimoda et al. Whereas. mangrove forests have been clear-cut. the more erosion and salt intrusion into land. etc. there is less nursery ground. efficiency.. 2011). and spawning ground for fish. Although there is not enough specific research about seawater quality close to shrimp farms in this province. quality.1). which is rooted in the “blue revolution”. In NTB. This concept is aimed to improve fishing. and fish processing in which aquaculture is the prime mover in this program. shrimp is one of the most produced seafood and it contributes to 8. These situations bring negative impacts on marine ecosystem because the less mangrove forest in coastal areas. This demand makes shrimp one of marine species developed for Minapolitan. Furthermore. is the concept of economic development of maritime affairs and fisheries regions based on the principles of integration.2
government of Nusa Tenggara Barat (NTB) (Figure 1. and speed.

2 An example of effluent produced by one of shrimp farms in Sumbawa Regency.4
For instance. in the Gangga sub-district. the community close to an intensive shrimp aquaculture practice complained due to the smell from water effluent produced and discharged to the sea. NTB. P. IMTA uses biofilters. P. According to a personal interview with A. NTB (Courtesy of A. specific species
. 2011) There is a new concept developed from polyculture called Integrated Multi-trophic Aquaculture (IMTA). August 12. 2011). which is known as a strategy for reducing environmental load from aquaculture ponds. one of the owners of shrimp and fish farms in that area. A similar concern also emerged from the community in Sumbawa Besar Regency. Putra. waste produced by aquaculture activity always distracted people living there due to the smell produced (personal communication.
Figure 1. Putra. personal communication. This approach is based on Ecosystem-Based Management (EBM) that expects people to maintain environment quality while utilizing the resources on it. North Lombok Regency. 2011). NTB. August 12. The community represented by the head of the Organization of Nature and Environment Observer of North Lombok Regency demonstrated their concern related to this issue (Lombokpost.

and Martin. Robinson. Shaw.9 tons (Central Statistical Agency of West Nusa Tenggara. For NTB. Oyster is also a species that has marketable value. total seaweed production of this province in 2009 was 147. Second is to help the government understand any negative impact on the environment that might emerge from intensification of aquaculture and produce a recommendation for the government of NTB.
This project has three main objectives.780 kg in 2001 to 740.
Implementation of IMTA for shrimp farms might be an effective way that should be considered by the provincial government in tackling any negative impacts caused by intensive shrimp farms in this area.
In addition. Indonesia.250. This number contributes to the GRDP of NTB. data shows the increase in oyster export from 79. This strategy has been implemented in some countries outside Indonesia with positive results related to environmental and economic aspects. For Indonesia. that have the ability to recycle nutrient or load produced by the main species grown (Lander. 2010). in particular. seaweed has marketable value.5
such as seaweed and oyster. IMTA is believed to bring more advantages for shrimp farmers due to additional revenue earned through selling biofilter species. in general. It may also benefit the coastal community in general since more labor forces are needed to operate a bigger scale of aquaculture practice and may also be used to reduce the accumulation of nutrients such as nitrogen in seawater. 2009). Third is to understand the nitrogen dynamics in an IMTA system because nitrogen is one of the most important nutrients that has a significant impact on seawater quality and sustainability of marine resources. 2009). a result of shrimp farms effluent. Determining
. First is to determine the possibility of IMTA in improving aquaculture practices in NTB.535 in 2008 (Central Statistical Agency of Republic of Indonesia. which makes this species reasonable to grow.

6
nitrogen dynamics in this system will be done using mechanistic modeling. This model is expected to explain the influence of parameters used in this model on final nitrogen output.
.

it is classified into three types based on management scale (Egna & Boyd. 1992). For an aquaculture pond in particular. and then recirculated and used for penaeid breeding system (Fast and Lester. First are open systems in which abstracted water is pumped from its source. aquaculture brings revenue because the cost is less than the value of product produced (Egna & Boyd. There are some common confinements used in aquaculture. manures and fertilizers. The second are closed systems in which water is biologically filtered for removal of ammonia excretory products of cultured animal. 1997).
As an economic activity. The first type is an extensive aquaculture pond in which the production can be improved by adding manures or chemical fertilizers. heated as required. 1992). sometimes prophylactically treated with EDTA. sometimes disinfected. 1997).
There are also other classification of aquaculture ponds. but manures and chemical fertilizers also may be used. 1997). and passed through culture tanks at 100 to 500% per day (Fast and Lester. based on seawater system. The second is a semi-intensive aquaculture pond in which feeds are used to increase the production. filtered or settled for removal of suspended particulates. cages.1 Aquaculture
Aquaculture is the cultivation of aquatic animals and plants to fulfill the human need of aquatic food organisms (Egna & Boyd. which include ponds. and pens.7
CHAPTER 2
BACKGROUND
2. raceways. and a mechanical aerator (Egna & Boyd. The last type is an intensive aquaculture pond that uses large amount of feed. 1997). Some other benefits offered are prevention of
.

In addition.5% of the total potential of worldwide sustainable fisheries (Ministry of Marine Affairs and Fisheries Republic of Indonesia.. deployment of pathogen. Indonesia
The potential of marine fisheries in Indonesia is about 6. Aquaculture production. This amount of production has supplied more than 50% of world’s consumption of fishery products (Conservation International. 2004). including Mollusks (oysters and sea cucumbers). 2007).8 million tons with value more than US$100 billion (Conservation International.6 million tons per year. is about 528. and pearl.
The development of aquaculture in many countries has historically been a positive development. and prevention of conflict between stakeholder using marine resources (Neori et al. seaweed.4% per year since 1970. 2011).
2.8
ecosystem degradation. and Social Economy in Nusa Tenggara Barat (NTB) Province. 2007). Egna & Boyd (1997) also mention that more and more farmers are starting to increase the intensification of their aquaculture in order to improve their production. 2011). In 2008. exotic species escape. Egna & Boyd (1997) mention that ponds are very important type of aquaculture because approximately 75% of total aquacultural production comes from ponds if only fish and crustaceans are considered. the growth rate of this sector is 8. 2007).
. total fishery products from this sector had reached 65. Indonesia is a country whose fishery production is the sixth largest in the world (Ministry of Marine Affairs and Fisheries Republic of Indonesia. or 7. According to Conservation International (2011).400 tons with the value of production US$ 567 million (Ministry of Marine Affairs and Fisheries Republic of Indonesia.2 Aquaculture Products.

2. aquaculture has become an important livelihood for people. or 40% of the total number of people employed in the fisheries sector (Food and Agriculture Organization of the United Nations. the number of people employed in fishing in general was about 5. In Ekas Bay for example. 2007). Communication and Information of Bima Regency (2008). Another example is Sumbawa Island (one of islands in NTB showed on Figure 1. Indonesia
One of shrimp species grown in Indonesia is Penaeus monodon.34% of the total population. 2011). This activity contributes 4.05% of total household employed in the fisheries sector in Indonesia. Aquaculture in this country has provided livelihoods for approximately 2. NTB is the third biggest shrimp producer in Indonesia (after Lampung and South Sulawesi provinces). which is dominated by intensive shrimp farming
. the contribution of this sector was 2.000 tons per year.7% of Indonesian Gross Domestic Product (GDP) (Ministry of Marine Affairs and Fisheries Republic of Indonesia. in 2007. in Bima regency (one of regencies in NTB).
In NTB. In particular. 1992). according to Department of Transportation. This species is native to Indonesia (Fast and Lester.1 Some of Main Products of Aquaculture in NTB.34% of total households in NTB and 0.384.2. 2007). In 2003.1). one of the coastal areas in NTB (Figure 1.208 households.86% to Gross Regional Domestic Product (GRDP) of this regency (Enirawan. 2011). This number is about 0.1). aquaculture has involved approximately 3. the volume of shrimp production in this province reaches 28. Furthermore. Additionally.9
This country has also developed aquaculture as an effort to increase fishery production.000 households (Wisnu. 2004). aquaculture contributed to one-fifth of total of fishery production in the country (Food and Agriculture Organization of the United Nations.

228. which contain heavy metal waste (Suara NTB. 2007) or about 0. the value of shrimp production in NTB was US$ 1.12% of total household in NTB. 2008). which serves as a host for pathogens (Panjara.940 (based on exchange rates of US$ and Indonesian Rupiahs on June 1 st 2012) (Central Statistical Agency Republic of Indonesia. also can cause shrimp to die (Suara NTB. and East Lombok (Department of Transportation. 2008). in NTB. This condition might directly
. In addition.773.113 households (Marine and Fisheries Agency of Nusa Tenggara Barat. the total area used for shrimp ponds in NTB is 22. 2011).000 ha and these areas are located in Sumbawa Island. West Lombok regency.
In 2009. Communication and Information of Bima Regency. a virus which usually infects shrimp in this region. Sa’diyah. & Kusumo. Central Lombok. 2011). one of the regecies in NTB. whereas only 10% is managed by local people (Department of Transportation. Furthermore. diminished sharply from 74.000 ha.
Overall. the data shows that there has been a recent decline in shrimp production. 2008). 2010).3 tons (Zaini. This might be due to disease. Communication and Information of Bima Regency. thousands of shrimp in some farm locations die due to flooding waters from illegal gold mines. For instance.
Despite the fact that total area used for shrimp farms is 22. the production of cultured shrimp in West Lombok. 2010). which can emerge after 1-2 months of stocking due to the increased organic load within the shrimp pond. the number of household raising shrimp in this province has reached 1.10
having a total production of 21 tons per harvest (Department of Transportation. “White spot syndrome virus' (WSSV). Businessmen from outside the province manage ninety-percent of this area. 2011). Communication and Information of Bima Regency.4 tons to 27.

551.857.2 Production of shrimp of NTB and Indonesia in 2009
NTB production Indonesian production Percentage of NTB’s production (Marine and Fisheries Statistical Data.715.325 2003 115.059.2.024 2009 99.744.283 2006 135.1 Export shrimp and prawns frozen of Indonesia Year Export (kg) 2000 97. Table 2. and 2.160 2005 121. But I ndonesia’s shrimp exports have recently decreased from US$102 million in 2000 to $91 million in 2001 and only $49 million in 2002.393.402. 2.691 2001 108.11
affect the total shrimp export in Indonesia since NTB is one of the biggest shrimp producers.856. This trend can also be seen between 2000 and 2010 as shown on Table 2.301 2002 104.328.027 2008 115. the average productivity was 2.884 2007 112.222 kg/ha for China and 800 kg/ha for Thailand).
Table 2.900 kg per hectare (compared to 1.661 2004 114.495 2010 99. During 1998-1999.1. 2011)
25.3.021tons 7.727 tons 337.633648942%
.387.945. 2011a).551 (Central Statistical Agency Republic of Indonesia.

2011).2% of the total population (Department of Industry.000 people or about 0. 2011). Trade. In 2007.3 The Value of Shrimp Production of NTB and Indonesia in 2009
The value of NTB’s shrimp production The value of Indonesian shrimp production Percentage of NTB’s value (Marine and Fisheries Statistical Data. The production of seaweed in this province has made NTB as the second largest producer of seaweed in Indonesia after Nusa Tenggara Timur (NTT) (Department of Industry. which was 16.011. 2011).
In Sumbawa regency. one of the regencies in NTB. 2011).13% of the total NTB population (Department of Industry. it could generate approximately 6. In this regency. this regency produced 13 billion Rupiahs.419. and small and medium enterprises (SME) of Pontianak Government.000 Rupiahs 8. Trade.790. seaweed farms employ approximately 849 people which is 0.3 billion Rupiahs in additional revenue (Department of Industry.5% of the value of regency total potency of natural resources. and small and medium enterprises (SME) of Pontianak Government. seaweed has become a primary commodity (see Tables 2.135. and small and medium enterprises (SME) of Pontianak Government.4 and 2.5). The number of people who work on seaweed farms has reached 6. Furthermore. The development of this sector might provide more job opportunities for those living in coastal areas (mostly poor) and contribute to an increase of
.570.12
Table 2. Trade. and small and medium enterprises (SME) of Pontianak Government. 2011)
1.200. if all potential areas were utilized for seaweed farms.000 Rupiahs 11.744843196%
Seaweed (also known as macroalgae) is another aquaculture commodity developed in NTB. Trade.

So far.127.964 2010 123.118.922. the international market for seaweed from NTB shows a good prospect.496 2003 34.250. and small and medium enterprises (SME) of Pontianak Government. 70% of seaweed needed by China as a raw material comes from Indonesia (Secretariat of Competitive Eminent Program of NTB. 2011a).
The potential of seaweed farms in NTB reached 22.027. 2011).000 Rupiahs 7.073.000 Rupiahs 4. and this number has not counted needs from other countries.588. 2012).952 2004 50.790.079.961 (Central Statistical Agency Republic of Indonesia.256 2006 95.
368.
.074.374 2005 69. 2011). It was predicted that in 2012.002.800 ha with the production of dry seaweed per year at about 765 million tons (Secretariat of Competitive Eminent Program of NTB.075. For example.300.5 Indonesian Export of Seaweed during a Decade Years Export (kg) 2000 17.222.928 2002 24. 2012).13
GRDP of NTB (Department of Industry.055 2007 94.948. this export will reach 123.576 2009 94. Trade.
Table 2.274.64643451%
Table 2.000 tons of dry seaweed.739 2001 22.4 The value of seaweed production in NTB 2009 (in Rupiahs)
Value of NTB seaweed production Value of Indonesian seaweed production % of NTB’s value (Marine and Fisheries Statistical Data.398 2008 99.

Oysters are one of favorite bivalves consumed by Indonesian communities due to its protein content of approximately 67-gram per 100-gram dry weight (higher than beef and chicken) (Ministry of Marine Affairs and Fisheries Republic of Indonesia. and tastes good. Philippines. the Europian Union. personal communication. Table 2. August 16th.6 provides the history of oyster exports from Indonesia within 9 years. and Japan (Secretariat of Competitive Eminent Program of NTB. 2011a) Years
.K. 2011). 2012).
Table 2. oyster is easy to raise. personal communication. According to personal communication with one of shrimp farmers who also consumes oyster in Sumbawa regency (one of regencies in NTB) (A.K. 2011). Basyar. there has not been many intensive oyster (fit for human consumption) cultures in NTB although it might have a good prospect for domestic or international trade (A. However. a fact which makes it a common bivalve consumed by community around that area.6 Export of Oyster Fit for Human Consumption of Indonesia
Export (kg) 2000 174151 2001 79780 2002 304873 2003 502235 2004 329290 2005 162904 2006 205171 2007 294371 2008 740535 (Central Statistical Agency Republic of Indonesia. Basyar.14
including America. August 16th. 2010c). does not require special treatment.

Minapolitan expects the development of marine and fisheries sectors to be pursued through acceleration of production of
. and pro -growth” (Ministry of Marine Affairs and Fisheries of Republic Indonesia. pro jobs. quality. 2011b). 2011b). It is based on principles of integration.15
2. the Marine and Fisheries Minister of the Republic of Indonesia developed Minapolitan (Ministry of Marine Affairs and Fisheries of Republic Indonesia. It is rooted in “Blue Revolution”. Through its vision and mission. 2011b). 2011b). and acceleration (Ministry of Marine Affairs and Fisheries of Republic Indonesia. there are still many poor people living in coastal areas. 2011b). but these have not been utilized optimally. the mission is “to prosper marine and fisheries communities” in accordance with the direction of development of Minapolitan which is “pro poor. In order to deal with this situation.42 million people who live in these areas. From 16. efficiency.
The vision of Minapolitan is the development of marine and fisheries sectors. 2011b). there is a need for a strategy to tackle this current problem (Ministry of Marine Affairs and Fisheries of Republic Indonesia.
In response. a fundamental change of the way of thinking from the mainland to the maritime with the concept of sustainable development to improve marine and fisheries production (Ministry of Marine Affairs and Fisheries of Republic Indonesia. Minapolitan is a concept for region-based marine and fisheries economy development.3 Policy Aspect related to Aquaculture in Indonesia and NTB in Particular
Indonesia has great marine and fisheries potential. Whereas. Regardless of all of this potential. 32% of them were those still living below the poverty line (Riyono. 2011). which will make Indonesia the biggest producer of marine and fisheries products by 2015 (Ministry of Marine Affairs and Fisheries of Republic Indonesia.

and fish processors fairly and evenly  develop Minapolitan as the center of economy growth
According to this policy. fish processors (Ministry of Marine Affairs and Fisheries of Republic Indonesia. fish farmers.
Some of core keys of Minapolitan are:
1. 4. An area that has facility and infrastructure that support economy activities. fish farmers. An area that employs and accommodates human resource within and around the area.
To implement Minapolitan program. 2. equitably. An area that has positive impact on economy around the area (Ministry of Marine Affairs and Fisheries of Republic Indonesia. productivity. one of the desired outcomes of Minapolitan is to increase the number and quality of marine businesses and upper-middle-scale fisheries in order to make them competitive. 2010). This regulation has several goals to:  increase production. 3.12/MEN/2010 about Minapolitan.
. and/or marketing. Marine and Fisheries Minister of the Republic of Indonesia issued Regulation of Marine and Fisheries Minister of the Republic of Indonesia Number PER. and other businesses such as service and trade. and quality of marine and fishery products  increase the income of fisherman. in 2010. and appropriately increase the income and the welfare of poor fishermen. 2011b). and that it will fairly. An economic region which includes center of production. processing.16
high quality and highly competitive products.

Indonesia has 1. The number of fishing industries (done by fishermen) is more than 17. there will be 6 regencies developed (Ministry of Marine Affairs and Fisheries Republic of Indonesia. Particularly. whereas. 2010b) (Figure 2.04% and 6.
As a follow up of this regulation. One of provinces that will be established is NTB.783 tons with value US$2. in 2011.916.17
In the same year. 2. the Marine and Fisheries Minister of the Republic of Indonesia also issued the Decision of Marine and Fisheries Minister of the Republic of Indonesia Number KEP.
. 2010b).530 ha that have been utilized.18/MEN/2011 about General Guideline for Minapolitan.300. This establishment was planned to be enacted between 2010 and 2014. but land ownership per capita is low and their lives are miserable.076 ha of land potential for developing aquaculture ponds.41% within 2006 and 2007. 4. According to this decision.000. only 612. Export fisheries product was 857. there will be 197 target locations within 33 provinces in Indonesia practicing Minapolitan (Ministry of Marine Affairs and Fisheries Republic of Indonesia.000. The number of labor forces working on aquaculture farms are 2. but most of them are traditional.
Some of the reasons for issuing this guideline are:
1. but this production declined 7.000 people. 3.32/MEN/2001 about Establishment of Minapolitan Area.1).224. 2011b).06% respectively) (Ministry of Marine Affairs and Fisheries of Republic Indonesia. the volume of shrimp export and the value decreased (5. and within this province. Marine and Fisheries Minister of the Republic of Indonesia issued Decision of Marine and Fisheries Minister of the Republic of Indonesia Number KEP.

facilities for production. 2011b). 2011b). aquaculture will be the center of fisheries production with high production. and road (Ministry of Marine Affairs and Fisheries of Republic Indonesia.18/MEN/2011 about General Guideline for Minapolitan is aquaculture. 2011b). electricity. and opening new aquaculture lands Revitalization of infrastructure for production such as irrigation. productivity. a provincial government
.
In accordance with the Decision of Marine and Fisheries Minister of the Republic of Indonesia Number KEP.18
The intention of this guideline is to equalize the perception of the system of marine and fisheries development through the concept of Minapolitan.
One of the Minapolitan strategies mentioned on Decision of Marine and Fisheries Minister of the Republic of Indonesia Number KEP. and infrastructure supporting the production
 
Revitalization of facilities for production such as ponds. and to increase the effectiveness of implementation of Minapolitan and acceleration of marine and fisheries production enhancement in accordance with Minapolitan (Ministry of Marine Affairs and Fisheries of Republic Indonesia. and pro-farmers through intensification and extensification (Ministry of Marine Affairs and Fisheries of Republic Indonesia. quality.
Some of the activities in this strategy are:  
The establishment of a center for fisheries aquaculture production Increasing accessibility of farmers toward marine resources.32/MEN/2001 about Establishment of Minapolitan Area. The strategy focuses on aquaculture potential.

2. 2012)
One of areas in this province. 2011).4 Potential Environmental and Other Impacts related to Shrimp Aquaculture
In order to produce pond-raised shrimp.1 Location of Minapolitan Areas for Seaweed in Province of NTB (Secretariat of Competitive Eminent Program of NTB. the shrimp must be fed (Bosma and Verdegem. will be developed into mega Minapolitan in 2012 in which shrimp and seaweed are the main commodities expected to contribute to 11. Saleh Bay. and the rest of this nutrient remains uneaten (Bosma and Verdegem. the growing shrimp utilize a small fraction of the feed. 2011).
Figure 2. 2011). the nutrient utilized by shrimp for their growth is only 24% of nitrogen and 13% of phosphorous of feed input.19
of NTB has started to develop Minapolitan areas. the rest
. In shrimp farming. the base for Minapolitan development is aquaculture (Fajarwati. 2010). However.6 trillion Rupiahs of the value of fisheries production (Akhmad. For NTB in particular.

5-25% N. p. unsanitary water. drugs etc. which come from effluent from aquaculture activities.p. and a perception that aquaculture can cause environment degradation. 2001). These numbers are lower than land-based marine salmon farms that produce waste equivalent to 17 people for N
.. 2006). Aquaculture practices release effluent containing high level of nitrogen and phosphorous.20
of their feed stays in the pond water (Shimoda et al.
Robledo and reile-Pelegrín (as cited in Seckbach and Dubinsky. The problems are causing the growth rate of aquaculture to decline. Bosma and Verdegem (2011).. the success of this practice has resulted in challenges as well: by-products and waste in water outflows to the environment. including the deterioration of the marine environment. 38-46% OC. However. 2011. 20% organic carbon (OC). According to Abreu et al. and 5-18% P are retained in the harvested production. shrimp farms have evolved quickly in the last 15-years and allowed this industry to produce approximately 855. 369). (2011). Abreu et al. 2011). Whereas. this decline is caused by some issues related to fish quality..
Intensive aquaculture in land-based seawater tanks has been criticized because of the environmental impacts caused by the practice (Chow et al. and 35-86% P end up in the sediment (Bosma and Verdegem. 66-70% N. heavy metals. which are considered water pollutants (Chow et al. are found in water downstream. Also. 2011. 368) argue that in tropical and subtropical coastal areas worldwide. (2011) state that some materials such as suspended organic matter. of the total nutrients applied to semi-intensive ponds. 2001). Robledo and reile-Pelegrín state that intensive shrimp farms can produce a total waste equivalent to 73-85 people for nitrogen and 101-161 people for phosphorous per ton of shrimp (as cited in Seckbach and Dubinsky.500 tons shrimp in 2001.

2006). The excessive nutrients can also cause plankton blooms and sedimentation from dead organic matter (Egna & Boyd. it threatens the species growing in the pond (Egna & Boyd. which include organic pollution and eutrophication (Bosma and Verdegem. 1999). These situations lead to other processes such as the increase of anaerobic conditions and the release of toxic microbial metabolites (Egna & Boyd. but also other organisms within marine ecosystem. 2011). excessive amounts of ammonia can limit the production (Bosma and Verdegem. p. 2011). diseases led to mass mortality due to the low water quality in the ponds (Bosma and Verdegem. Effluent from shrimp ponds.
. Decomposed excess feed and feces are poisonous materials for other organisms and can inhibit their growth (Andriani. (2006) also demonstrate that ammonium.
The increase of intensification of aquaculture leads to the increase of manures. Unfortunately. discharged to the sea leads to degradation of sea water quality (Shimoda et al.
Shimoda et al. 1997). When the concentration increases to toxic levels. fertilizers and feeds used (Egna & Boyd. Msuya et al. There are also risks inherent to aquacultural practices. Indonesia. in some countries such as Vietnam. (2006) add that in shrimp pond aquaculture. 1997). which consists of accumulation of nitrogen and phosphorus. 368). and Philippines. Not only does this condition threaten the organisms inside the ponds. nitrogen and phosphorous are discharged into the environment in the form of particulate organic matter rather than in the form of nutrients. For instance. in this kind of intensively fed aquaculture. derived from feed and other suspended solids.21
and 12 people for P per ton of fish (Robledo and reile-Pelegrín argue this as cited in Seckbach and Dubinsky. is the main polluting waste from ponds effluent. 2011.. 1997). 1997). after 3 to 5 years of successful culture. 2011).

waste produced by the shrimp farm nearby disturbed neighbors due to the smell produced (personal communication. (2009). This approach can improve nutrient utilization efficiency
.. which are specific species that have ability to recycle nutrients or the load produced by the main species cultured (Lander et al. P. the community near a shrimp farm complained due to the smell from water effluent produced and discharged to the sea by the farm (Lombokpost. NTB. which consists of nitrogen discharged to the sea (Wibisono. issues of seawater pollution are known. The increase of aquaculture production from 234. This type of aquaculture practice uses biofilters. in Gangga sub-district. August 12.. The impact of this kind of water effluent has also triggered reaction from the communities surrounding the farming area. The community represented by the head of Organization of Nature and Environment Observer of North Lombok Regency demonstrated their concern related to this situation (Lombokpost. V.
IMTA can be considered a potential method to improve aquaculture production through multiple cropping (Pantjara et al. Putra.. although there is not enough specific research about seawater quality close to aquaculture ponds.. 2011). 2011). R. A similar concern also emerged from the community in Sumbawa Besar Regency. with the converted nutrients used as a food source to support their growth. T. NTB.000 tons in 2008 has caused the increase of waste from effluent..
2. 2010). 2011). Chayati.22
In Indonesia. N. According to personal interview with A.5 Integrated Multi-trophic Aquaculture as an Application of Ecosystem-based Management
Integrated multi-trophic aquaculture (IMTA) is a concept developed from polyculture.966. For instance. 2009). Ardhitio. C.900 tons in 2002 to 1. North Lombok Regency. biofilter species are able to convert dissolve inorganic and suspended organic nutrient in pond water. According to Abreu et al. 2011).

where antagonistic encounters between the different species are minimal. Another study at the same research center comparing monoculture crop (shrimp) with IMTA (shrimp) using seaweed also showed that the B/C ratio resulted from IMTA is 1.54 and profitability 64. which is the largest abalone producer in the world (Nobreet al.(about $590) per growing season with B/C ration 1.277. Indonesia. which is higher than shrimp monoculture (0. Even though this study did not compare IMTA with monoculture crop.
Studies exploring the implementation of IMTA have been conducted in many parts of the world including South Africa.64..82) (Hendrajat et al. 2004). shows that with the increase in density of biofilters used for shrimp ponds. The application of IMTA might bring some additional advantages including reducing cost for seawater pumping (due to recirculation of water) and reducing effluent discharge (that contains excess nutrients) (Neori et al.6%.21% (Pantjara et al.000. whereas in the low density biofilter systems.977. there would be less risk of shrimp mortality and higher production by about 14..
An experiment conducted in Research Center for brackish water aquaculture. 2010). the revenue earned is Rp 5. Pantjara et al. 2010). it could be seen that the presence of biofilters might lead to higher production and revenue. in higher density of biofilter systems.000.6% (Pantjara et al.. 2010)..07 and profitability 116.(about $1300) per growing season with B/C (benefit/cost) ratio 2.23
because waste produced is considered a resource for biofilters (Bosma and Verdegem. the revenue earned is Rp 10. 2011). South Sulawesi. 2010). Bosma and Verdegem (2011) also add that this system can improve nutrient recovery in aquaculture ponds through providing feeding niches for different species that partially overlap. Furthermore. (2006) stated using biofilters for shrimp ponds allowed the shrimp to be more resistant toward disease (virus)..
.. In addition.

sediment. crustacean.1 Oyster (Crassostrea sp. (2011).. Crassostrea sp.. IMTA implemented in Bali has shown good results and optimization of feed usage (Wibisono et al..
. and mollusk producer in the world (Food and Agriculture Organization of the United Nations. Tandencia. 1995)... These studies have shown better results (higher production) from the use of biofilters compared to production from monoculture (single crop). In particular. Oysters can reduce suspended organic and inorganic matter. 2008).
2. which uses shrimp and seaweed. bacteria.24
Chile (Neori et al. Green mussel might also be used as a biofilter due to its ability to absorb heavy metals. These two species might be able to reduce the environmental load. IMTA is being partially implemented and only in some areas. Robinson. In particular. shows that filter-feeding mollusks have been known as biological filters for shrimp ponds effluent (Hurtado-Ponce.. 2010). including Cirebon and Indramayu. 2006). and oysters (Wibisono et al. West Java.5. and China (Neori. phosphorus. phytoplankton. 2010c).
According to Wibisono et al. and to inhibit eutrophication processes (MacDonald.) as Biofilter
Work in Thailand and elsewhere. 2011). and excessive nutrients from its environment (Ministry of Marine Affairs and Fisheries Republic of Indonesia. and Bali using fish. et al. (Shimoda et al. 2007) is the biggest fish. in Indonesia. 2011). 2004. 2006). and other distracting materials in ponds. seaweed. chlorophyll a. has the ability to reduce excessive nutrients.. 2011). 2008). 2004) is the biggest seaweed exporter in the world (Food and Agriculture Organization of the United Nations. heavy metals (Fe2+) (Pantjara et al. nitrogen. Oysters and seaweed can be used as biofilters in shrimp systems (Shimoda et al. & Barrington.

Conceptual models are the initial application of
. 1995. 2010). 2010.
2. (2009) mention that Gracilaria sp. 2007). Pastres. (2006) also demonstrate that the presence of seaweed in ponds makes ammonia concentration in the ponds lower. Pantjara et al.
2. as biofilter.) as Biofilter
Studies in Thailand and elsewhere also suggest that seaweed is a nutrient-absorbing species that can be used as a biofilter for shrimp pond effluents (Hurtado-Ponce. & Pecenik.5. Soetaert & Herman.6 Modeling for Nitrogen Dynamics in Shrimp. as biofilter.25
(Tendencia. This species is tolerant toward brackish water and has the ability to absorb heavy metals such as Al3+ (Pantjara et al. a model is a simple representation of a complex phenomenon and an abstraction that does not contain all the feature of the real system. Oyster. low productivity of shrimp ponds can be improved using Gracilaria sp. 2010). (2010). growth also shows a good performance if it is located close to salmon cages. 2009). Modeling is one solution used to understand coastal ecosystem dynamics as the result of anthropogenic perturbation or a certain phenomenon. and Seaweed Cultures
According to Soetaert & Herman (2009). It also absorbs Fe2+ more than 1000 mg/L used as electron conductor within enzymatic system and enzymes formation for amino acid metabolism (Pantjara et al.. Abreu et al.2 Seaweed (Gracilaria sp.. Shimoda et al. 1995). France. to extract quantitative information. (2010) demonstrate that low productivity of shrimp ponds can be improved through utilization of Crassostrea sp. Besides being placed together with main species grown within the pond. According to Pantjara et al.. 2010). and to make a prediction (Solidoro. Dejak. and absorbs some ions such as sulfate and phosphate used for agar formation (Pantjara. Hendrajat et al. to make time and spatially averaged budgets.

a strategy for managing ecosystem can be determined (Solidoro et al. Soetaert. in aquaculture. For instance. Mechanistic model can also be used for extrapolating in space and in time (Soetaert. All relationships between the components are then put together and measured using a set of
.
Second is mechanistic/analytical model. & Herman. a model can depict the growth rate of algae. Empirical models are appropriate when a situation is similar to the conditions where data was collected to make this model (Egna & Boyd. 2009).
There are two main types of models for aquaculture pond processes. 1997). which involves the uptake of nutrients from the environment and feeding zooplankton on algae which leads to transfer of biomass from algae to zooplankton (Soetaert & Herman. and settling). First is an empirical model. The conceptual model for aquaculture ponds depicts the mass flow between biomass components (fish. and detritus). Through this approach. 1997. this model is unable to provide an explanation about how each individual component functions within the system analyzed (Egna & Boyd. 1997). which means that every single component affecting and affected by other component is identified (Egna & Boyd. modeling is an approach used to analyze and organize information and knowledge about the dynamic of aquaculture ponds. 2009). and death). and possible avenues for material entering and leaving the pond (Egna & Boyd. zooplankton. 2009). 1997). grazing or feeding.
According to Egna & Boyd (1997). 1995). which is based on statistical analysis of data (Egna & Boyd.26
modeling and these are used as the foundation for building a computer-based simulation model (Egna & Boyd. However. physical processes (resuspension. & Herman. suspended and benthic microfauna. biological processes (production. 1997). 1997). phytoplankton. This type of model is based on paradigms about how a system works. respiration.

which are a lack of accuracy and it is overly complex (Egna & Boyd.27
equations (Egna & Boyd. and bacteria (Bacher et al.
Many studies using mathematical modeling for intensive aquaculture consider nitrogen as a currency measured since nitrogen plays a key role in the dynamics of aquaculture systems (Burford & Lorenzen.. However. 2004). 2004). 1997).) (Bacher et al. zooplankton. 1995). 1995). For the purpose of analyzing the nitrogen dynamics in shrimp ponds. This model is more applicable than the former one. 2010). including assimilation by phytoplankton.. nitrogen was assumed to be generated from shrimp feeding on formulated feed (Burford & Lorenzen. and discharge during water exchanges (Burford & Lorenzen. 1997). 2004). 1995). including
. Previous studies have focused on the spatial and temporal variability of the main variables or components in this ecosystem: including phytoplankton. phytoplankton grazing by the oyster. comparison between phosphorous and nitrogen concentration in semiclosed oyster culture shows that nitrogen was the limiting factor (Bacher et al. and exchanges between sediment and water (Bacher et al..
Nitrogen has also been used as a currency for modeling the relationship between nutrient input and cultivated oysters (Crassostrea sp. volatilization. 2004). but it also has shortcomings. nitrification. Nitrogen has dual role in various forms as a nutrient and a toxicant (Burford & Lorenzen. focusing on the nutrients. there are some ways that nitrogen can be transformed. The simple model used to assess the impact of oyster activity on nitrogen dynamics can include primary production. nutrients. There are some currencies commonly used in modeling seaweed. From this source. 1995)..
Ecosystem models are also an appropriate method for scaling the role of seaweed to the system level and to forecast the potential interaction between nutrient and seaweed proliferation (Brush & Nixon.

respiration. et al. 2010). Indonesia (Shimoda.28
carbon. and other engineering tools. mangroves. data is needed from that kind of experiment. building ponds. 2010). In particular. nitrogen. and no known experiment in NTB. which are oysters. seaweed. and biofilters. In order to build the mechanistic model. There is one in South Sulawesi at Research Institute for Coastal and Fisheries. the coupling of a seaweed sub-model with parental ecosystems can include rates of nutrient uptake and release. This experiment used shrimp as main crop. Biomass dynamics of seaweed in this model represent the balance between primary production..
.. and light attenuation through the overlying water and phytoplankton (Brush & Nixon. described in the previous section. oxygen production and consumption. Furthermore. and phosphorous (Brush & Nixon. 2006). et al. 2010). to determine the technical steps such as measurement of parameters. and loss by exchange to other spatial elements (Brush & Nixon. and sea urchins (Shimoda. decay. 2006). the further development of this study would be to work collaboratively with researchers that have done IMTA experiment before in Indonesia. So. grazing.
There are not many experiments for IMTA conducted in Indonesia.

29
CHAPTER 3
METHODS
3. (1995): The seaweed model was written by Brush & Nixon (2010). oyster. and the latest policy about fisheries in Indonesia gathered through searching relevant journals and data collection from a statistical agency in Indonesia. and seaweed from other places (Figure 3. and some shrimp farmers in Nusa Tenggara Barat (NTB) province where my study is focused: I also conducted some discussion with two officials in Investment and Regional Environmental Agency of Sumbawa. Secondly.2).1. The shrimp pond model was written by Burford & Lorenzen (2004): The oyster model was written by Bacheret al.1 and 3. Maros. I first collected information about IMTA. environmental concerns. South Sulawesi. Information and Data Collection
For this project. I worked with Dr. George Waldbusser to create a conceptual model for IMTA in NTB using three existing conceptual models for shrimp. to create a mechanistic model that can be populated with NTB-based data. Some discussion was also developed with a researcher who has done IMTA experiment in Research Association of Brackish Aquaculture. Waldbusser to build a mechanistic model). Third. Listed below are the three conceptual models that were combined and could be used for determining nitrogen dynamics in IMTA design. one of regencies in NTB.
.
Using the conceptual model and data adopted from previous studies (I then worked with Dr.

three models were created from different locations. and period of time. Although the mechanistic model has not been completed. These locations might have different temperature. the consequences of these limitations might be lack of accuracy of model that would be built. there is zooplankton as part of the model. light penetration. the studies did not consider the same parameters. oyster and seaweed) from other studies conducted in other places had been combined to create a single conceptual model for NTB. whereas two other models did not have zooplankton.2 Limitations related to the Data Available and the Conceptual Model
As mentioned before. For example. this study has limitations.
Therefore. all the governing equations and parameter values
. and combining many parameters into one model might increase the error of this model. In addition.3 Creating a Mechanistic Model for IMTA: NTB
In order to create this mechanistic model. and finally on the dynamic of nitrogen on the observed systems. such as an estuary. and the impact of different periods of time for observations or data collections. the mechanistic model that will be produced would be adjusted with the NTB-based data. Then. one of models developed was based on pond conditions. In one model. physical characteristics of environment.
3. whereas the other two models were based on different conditions.33
3. Lastly. salinity. three different conceptual models (for shrimp.
The mechanistic model that will be built will be processed using MATLAB (software). this single conceptual model will be used as a guide to build the mechanistic model. Finally. which might have different effects on the growth of the species.

In this case, temperature is exponentially expressed as oxygen consumption (mgO 2/hr/individual) and converted to energy through the multiplication by the factor.

Reproduction rate (according to Powell et al. (1992)) :

(16)

Excretion rate (gN/d individual):

(17)

Light irradiance at depth z:

(18)

Using data from Henard (1978), k was estimated from vertical profiles of the light availability at different location. Since there is no relationship between the estimated k values and environmental data (chl a, turbidity), k was constant during the simulation.

(19)

(20)

Phytoplankton growth rate:

(21)

biodeposits. Z.
(26)
The diffusion from the sediment:
(27)
. which resulted in a vertical nitrogen flow (gN/m3/day). The settling rate was defined by the product of the appropriate sinking rate and the concentration.40
Mortality rate of phytoplankton:
mortality = mp. P. 1991):
This parameter depends on phytoplankton
(23)
Mortality rate of zooplankton:
Mortality = mz. g(T)
(22)
Zooplankton grazing (Chapelle. g(T)
(24)
The function of temperature:
(25)
A sinking rate ks (m/day) was defined for phytoplankton. and detritus.

DS
(30)
.41
(28) Mineralization at 00C:
Mineralization in the water = mwD.g(T).g(T).D
(29)
Mineralization in the sediment = msD.

cove-wide estimates of irradiance reaching the bottom were computed as a function of k using Io and hypsographic curves for the system. These daily values were then converted to instantaneous values (Iinst. µEm-2 s-1) to drive macroalgal production using an empirically derived relationship for Rhode Island:
(34)
In which. f = photoperiod expressed as a fraction of a day from day one (January 1) to 365 (December 31):
(35)
Iinst is then attenuated through the Gracilaria mat using empirical measurements of light transmission as a function of dry weight in the layer (GRAClayerdw):
.44
Following are some governing equations used for this model: GRACN(t) = GRACN(t−dt)+(NGPPGRAC+NluxGRAC− NremGRAC− GGRACN− DGRACN − exch)dt DECN(t) = DECN(t−dt) + (DGRACN− NremDEC)dt (31) (32)
GRACdw is devided into a series of layers 1 cm thick using the relationship of Peckoll and Rivers (1996) to convert dry wright into mat thickness (GRAC cm):
(33)
Area corrected.

0025
(38)
Pm for Gracilaria: For T < 40.45
(36)
The light received by each layer is combined with a photosynthesis-irradiance relationship to compute hourly GPP of each layer (mg O2 g-1 dw h-1):
(37)
αGRAC = 0. converted to carbon units (PQ = 1) and a daily rate based on photoperiod: (39)
(40)
This potential rate of production is reduced to the actual rate ( GPP*) in the event of nutrient limitation: (41)
.0014T + 0. PmGRAC = 0 Potential total daily GPP (g C m-2 d-1) in each element is the computed as the sum of production in all 11 layers multiplied by the dry weight in each layer (dw layer). For T ≥ 40.

Uptake rates for each producer are then estimated from the hyperbolic relationship between nitrogen concentration and uptake rate:
(42)
The loss term for macroalgae include respiration. g C m-2 d-1) were initially modeled as exponential functions of temperature.13 (Brush and Nixon. 2003)
Grazing rates (G. decay and exchange via drift to other spatial element.
(43)
A loss of oxygen from the interstices between thalli in the layered mat led to declining weightspecific rates of respiration in Gracilaria with increased biomass layering:
(44)
The intercept
was set at 1.46
NUTLIMGRAC is a dimensionless term for 0 to 1 representing the fraction of GPP that can be supported by available nutrient based on the relative demands and uptake rates by phytoplankton and Gracilaria. grazing. with the 00C intercept and exponent set by calibration:
(45)
.

oyster. and mortality rate of crops (shrimp. From all of those parameters. To date. and salinity. temperature. it is important to recognize that there is a need of choosing the most effective parameters that influence how the model will work to determine the final nitrogen output from IMTA. Indonesia (recommendation for further study). such as volatilization. and seaweed).1) that there are some less important parameters. flow rate and water exchange.0:
(46) The rate of carbon decay is treated as a respiration term (g C m-2 d-1):
(47)
3. There is also a need to adjust the value of each parameter with the value of parameters that would be acquired from further experiment of IMTA in NTB. feeding rate. the most important parameters seem to be density. growth rate.4 Putting All the Parts Together from the Mechanistic Model
We have just laid all the parts from the mechanistic model. (1986) and assuming a Q 10 of 2. it can be estimated (from Figure 3. and DON concentration. light. Whereas.47
Decay rate of macroalgal carbon was driven as a function of temperature and tissue C:N ratio using regression of Twilley et al. zooplankton. sedimentation and remineralization.
.3.

4. a phenomenon in which there is less oxygen in seawater than that needed for marine organism growth due to competition in using this oxygen. 2011). together with shrimp feces.1 Understanding the Dynamics of Nitrogen in Shrimp. 2011).. The problem does not only affect the shrimp production. is a pollutant that obstructs shrimp growth because it declines water quality in the ponds. Water containing rich nutrients can fertilize other organisms in marine areas and lead to hypoxia. this creates problems for organisms living there..1. intensive aquaculture companies without recirculation systems will discharge an effluent highly enriched with ammonium (Abreu et al. This inevitably will threaten marine ecosystem sustainability and coastal community’s livelihood. Oyster. As result. The low quality of water used to raise shrimp in ponds can attract virus and bacteria that lead to shrimp disease and death.48
CHAPTER 4
DISCUSSION
4. On the other hand. This material. which is dependent on marine resources. but also other marine organisms because as the water effluent from shrimp ponds is discarded to the sea. but it is not fully used by shrimp.1 Parameters that Affect Nitrogen Dynamic in Shrimp Ponds
There are seven parameters considered to be important in shrimp pond that affect nitrogen output from this system based on previous study by Lorenzen (2004). there is an accumulation of non-used nutrients. and Seaweed Ponds
Shrimp feed contains some nutrients needed for shrimp growth. Each is described below.
.
In general the nitrate fraction is higher in the outflow of semi-intensive systems than in intensive fish farms with water recirculation practices (Abreu et al.

the volatilization rate of ammonia (TAN) is approximately 5% of TAN per day and this number is higher than that of in-channel catfish ponds. high pH. According to Burford & Lorenzen (2004). in shrimp ponds. Boyd & Tucker (1998) suggested that ammonia volatilization was considered unimportant.
.
In the IMTA concept designed for this project. the higher volatilization rate. Burford & Lorenzen (2004) mentioned that volatilization rate could decrease with the increasing water exchange rates. 1998. which is 4%. However. However. the effect of wave formation can be ignored. which is a semi-closed system. This suggests that we can reduce the amount of total nitrogen through inducing more volatilization. 1998). The loss of ammonium from water through volatilization might be an important path in reducing the total nitrogen concentration in the water.49
Parameter 1: Volatilization Rate of Ammonia
Volatilization tends to be experienced by un-ionized ammonia (that can be toxic to aquatic animals). 2004). The higher these factors. this gas is not lost quickly into the atmosphere because of high solubility (Boyd & Tucker. for modeling purpose. This suggests the IMTA concept designed will have less volatilization since it is assumed to have water exchange. and high turbulence and wave formation during periods of windy weather (Boyd & Tucker. which is a dissolved gas. but the effect of windy weather which shears the surface of water in the pond may be important. Burford & Lorenzen. There are three factors influencing the rates of volatilization including: high concentration of ammonia in the water (can be due to high stocking density). However. such as increasing turbulence.

the more N might be found in the water. the nutrients utilized by shrimp for their growth is only 24% of nitrogen input (Shimoda et al. the feed might not be sufficient for shrimp and will lead to slower growth rates or cannibalizing shrimp. the feeding rate needs to be considered since it is known as an important parameter that affects N input. and in fish farms. When the farmers feed the shrimp at a high rate. The increase in stocking density together with feed inputs using manufactured feed (containing nitrogen as a constituent of feed protein) can lead to the increased shrimp excretion.50
Parameter 2: Shrimp Stocking Density and Feeding Rate
Stocking density and feeding rate are important parameters that influence the total nitrogen concentration in the pond. 2006) (might be due to low storage capacity of nutrient by shrimp). the increase in stocking density above 60 animals/m2 would result in an unacceptably high TAN concentration in the water (Burford & Lorenzen.. particularly from feed. However.
.
Even with water exchange rates of 7% per day. if farmers try to lower the feeding rate in order to produce less nitrogen. This is a general condition that happens not only in shrimp farms. Nitrogen input. 2004). is not fully utilized by shrimp for their tissue development and it accumulates in the sediment. In intensive shrimp farms. fish harvest accounted for about 20% of the total nitrogen input Boyd & Tucker (1998). This suggests that we need to be careful in deciding how much shrimp larvae should be grown per growing period so that the accumulation of N in the pond will not disturb shrimp growth. In addition. but also in fish farms.

many wastewater treatment plants need to achieve very low levels of total nitrogen (3-4 mg/L or lower) in the effluent. in order to prevent eutrophication in receiving water. TAN (inorganic nitrogen) is mostly generated from shrimp excretion. in the U. for the IMTA conceptual model design. the effluent DON concentrations can approach 1 mg/L or higher and can constitute one-third to one-half of the effluent total nitrogen that a wastewater treatment plant will need to attain to maintain permitting (Murthy. 2006). In many cases.
However.51
Parameter 3: DON Concentration
Dissolved organic nitrogen (DON) concentrations can increase with an increase in feeding rate. and therefore is assumed as an isolated pool. Jones. DON component is included within these total nitrogen limits. Burford and Lorenzon (2004) also mentioned that DON concentration increased with increasing stocking densities. it can be assumed that although DON can be significantly influenced by the additional stocking density and feeding rate.S. except if there is mineralization happening. Burford and Lorenzon (2004) suggested that much of DON is refractory and not readily used by primary producers.
Parameter 4: Total Ammoniacal Nitrogen (TAN) Concentration
As mentioned before. even though its concentration is considered significant.. the presence of this compound in the pond is not very important in effecting eutrophication. for example. A model adopted for this project run by
. and remineralization of waste feed. according to regulatory agency. its concentration will be less important for final inorganic nitrogen output from this system. So. but were not affected at all by sludge removal rates. Baidoo & Pagilla. decomposition. DON is a nitrogen source that is not readily used by plants. So.

this value increased rapidly (exceeded phytoplankton uptake capacity) and reached 1. This makes the process of sedimentation and remineralization very important in influencing nitrogen dynamics in shrimp ponds. which can be toxic (more toxic than nitrate). If there is high rate of remineralization followed by high stocking density. which is the conversion of organic nitrogen into inorganic nitrogen through a biological process mediated by bacteria. the median lethal concentration of ammonia range from 30 and 110 mg/L TAN depending on size and age (Schuler. All these numbers suggest that TAN concentration can be reduced through increasing sludge removal.6 mg/L at the end of the growing period. which are less than 0. 2004). the inorganic nitrogen (TAN) is carried back to the water column.52
Burford and Lorenzen (2004) predicted that. 2004). TAN concentration reduce to 20-30% (Burford & Lorenzen.
Parameter 5: Mass of Nitrogen in the Sediment and Remineralization of TAN
Decomposition of decaying biota such as phytoplankton is the main source of particulate inorganic nitrogen accumulated in the sediment. Burford and Lorenzen (2004) also suggested that at high stocking densities (>100 animals/m2). TAN levels increased with decreasing water exchange rates and increasing stocking densities (Burford & Lorenzen. However. the first 100 days of growth has low TAN concentration. When the sludge is removed from the bottom of the pond in the rate of 10-20% per day. and lowering stocking densities. it can be assumed that there will be high concentration of TAN in water column. water exchanges of 20% per day would maintain TAN concentration <4 mg/L and should not compromise shrimp growth.1 mg/L. 2008). increasing water exchange. For varying species of shrimp. in shrimp ponds. Through remineralization. Studies
. Furthermore.

but low concentration of oxygen. it would be better to pay attention to the concentration of this nutrient especially when it is contained by waste discarded to seawater to prevent the negative impact. 1992).
.2 mg/L for nitrate (Fast and Lester. The normal seawater value is 0.1 mg/L (Fast and Lester.
Parameter 6: Nitrate /Nitrite (NOX) Concentration
Nitrate/nitrite concentration is influenced by the stocking density.04 mg/L for nitrite and 0. a suggested guideline is NH4-N.05 mg/L (Fast and Lester. 2008). the NOX concentrations were relatively low (<1 mg/L).01-0. Burford & Lorenzen (2004) mentioned that at low stocking densities (<50/m2). whereas. 1992).1 to 0. which serves to inhibit the nitrification. However. Whereas. Nitrification rates have generally not been well studied in intensive earthen shrimp ponds with water exchange. 1992) in order to prevent eutrophication. The high concentration of TAN from shrimp pond effluent might also threaten many other aquatic animals. This might be because the high concentration of TAN. 2004). although increasing water exchange rates can reduce TAN in shrimp pond. One strategy in dealing with this situation is increasing water exchange rates. < 0.02-0. The concentration of nitrate/nitrite is generally low in pond system. Normal seawater value is 0. suggested guidelines for nitrite are less than 0.
However. but nitrate and nitrite concentrations generally remain low throughout the growth season (Burford & Lorenzen.53
with various species also suggested that the toxicity of ammonia to specific species is dependent on time and concentration (Schuler. this does not mean that the effluent from this pond can be safe for the environment.04 mg/L for NH4-N.

Water exchange can remove most of the phytoplankton in the pond. 2004). 2004). more decaying phytoplankton will sink and be deposited. this condition can have a negative impact. is highly anoxic. the more phytoplankton will be removed. which include water exchange and deposition on the floor. This sink does not hold the source of nitrogen in the form of phytoplankton. According to Burford & Lorenzen (2004). suggesting that the higher rate of water exchange. and TAN release will continue to rise. phytoplankton takes up the TAN and uses it to grow. When this condition happens.
Parameter 7: Concentration. we can assume that concentration of nitrate and nitrite are not as important as TAN in influencing the final output of nitrogen in shrimp ponds. but for receiving water body (seawater). this TAN will be put back to the water column.54
Regarding denitrification in the sediment. particularly the sludge. For the pond itself. Through assimilation. which shows that phytoplankton is an effective remover of TAN.
. there are two ways of phytoplankton removal from water column. and low concentration of nitrate prevents denitrification (Burford & Lorenzen. and Sedimentation Rate of Phytoplankton
Phytoplankton plays a very important role in the dynamics of nitrogen in ponds. 2004). this condition can reduce the negative impact of high concentrations of phytoplankton in the pond. Assimilation. which limits the phytoplankton production (Burford & Lorenzen. Significantly high concentrations of phytoplankton in water column can lead to self-shading. but the resulting detritus may be remineralized by bacteria to form TAN or buried in the sludge (N sediment) (Burford & Lorenzen. Additionally. According to this fact. The deposited phytoplankton is mostly dead or decaying phytoplankton. a previous study shows that sediment.

55
As additional information. The more phytoplankton available around the oyster. whereas the salinity should be maintained between 28 to 36 ppt (preferred 32 ppt) (Fast and Lester. will grow optimally in temperature between 27-290 C. particularly the species of Penaeus monodon.2 Parameters that Affect Nitrogen Dynamic in Oyster (Crassostrea sp. the presence of phytoplankton in an environment is believed to influence the biomass of oysters. because there would be less oxygen available for the oysters and a decrease in oyster feeding activity. Growth Rate and Biomass
Oysters feed on phytoplankton. Food consumption ranged from a low of about 10% to as high as 50% of body-weight-per-day (Malouf & Breese. Since phytoplankton are a source of food for oysters.
Parameter 1: Oyster Stocking Densities. 1978). excess phytoplankton concentrations in the pond might not be good for the development of oysters. oysters play an important role in controlling the quality of water. the waste can be converted into an edible product that has economic value. While shrimp tends to produce waste.e.
4. (1995) mentioned that a single oyster (with a mean weight of 50 g) filters about 4 l/hr. shrimp. So the whole oyster population can have a significant impact on environment. Oysters act as a nitrogen (large amount) trapper/sink when filtering the water and
. Bacher et al.) Ponds
Oyster cultures are one way to stabilize primary production (i. the higher biomass of the oyster can be. 1992). However. Through growing oysters. consuming phytoplankton). which leads to an increase of primary production.
As a filter feeder. whereas phytoplankton is a nitrogen sink. the presence of oysters can minimize this negative impact through filtering the waste and using it as a source of food and nutrients.1.

nitrogen dynamics are significantly influenced by phytoplankton that use inorganic nitrogen as a nutrient used for their growth. zooplankton had no effect on the nitrogen dynamics in the pond system.
Parameter 2: Phytoplankton
Phytoplankton productivity is affected by nutrient and light availability. The higher phytoplankton density. However. which are oysters that also feed on zooplankton.56
this nitrogen is partly recycled through biodeposition and oyster excretion (Bacher et al. This means that when the phytoplankton from the shrimp pond is channeled to the oyster pond. High concentrations of nutrients and food available to oysters can lead to higher growth rates and increase in biomass. the more nitrogen being removed from water. which makes zooplankton an important parameter that affects nitrogen dynamics. In IMTA pond design. according to the previous model.
Parameter 3: Zooplankton
Zooplankton is another predator for phytoplankton that plays a role in the aquatic food web. No light limitations and available dissolved inorganic nitrogen result in high growth rates of phytoplankton. oysters will be the sink of nitrogen since oysters feed on phytoplankton. The presence of zooplankton in oyster ponds did not seem to control the population of phytoplankton because there is a bigger predator. Through predation. This condition suggests that there will be less final output of nitrogen.. and the more nitrogen converts to oyster biomass. the nitrogen from phytoplankton is transferred to zooplankton.
Parameter 4: Sedimentation and Mineralization
. 1995).

Temperature generally affects the biological flow in oyster ponds. The thermal death
. However.
Parameter 5: Temperature
Temperature can affect primary production. Bacher et al. the primary production remained at low levels (approximately 0. Even though the temperature is optimum for primary producer growth.
For oysters in particular. oyster excretion and sediment release increased with temperature. when the temperature was around 80C. the primary productivity may be low.. 1995). (1995) mentioned that the sedimentation rates of particulate matter were doubled by the deposition of oysters because biodepostion can increased the amount of detritus in the sediment. The accumulated of nitrogen is from detritus.003 gN/m3/d) (Bacher et al. 1995). the effect of temperature on primary productivity is coupled with the availability of nutrients. which is the source of food for oysters. This source of nitrogen through mineralization is lifted into the water column in the form of inorganic nitrogen and can increase the final output of nitrogen from the pond. adult oysters are highly tolerant of extremes in ambient of temperature and are commonly found in waters where the annual range is from -2 to 360 C. if there is lack of nutrients. (1995) mentioned that the main nutrient flows. This means the water-sediment interface played a critical role in nitrogen regeneration (Bacher et al. This suggests that temperature dynamics in the pond are important.. Bacher et al. For example. resulting from primary production.57
Sedimentation is another sink of nitrogen in the pond. detritus mineralization.

1996). Enough light can let the primary producer increase productivity. This suggests that high temperature (beyond the optimum temperature) also can increase the final output of nitrogen from the pond. This high density of phytoplankton is a good source for oysters and can lead to an increase in oyster biomass. Malouf & Breese (1978) also showed that there is no growth advantage for water temperatures in excess of 150C. (1995) showed that during winter. This is mainly constrained by light. including oysters in the pond.50 C. since heated water can be supersaturated with atmospheric gasses and causes gas-bubbled disease (Malouf & Breese. 1978). the uptake rate of nitrogen by phytoplankton from the water will also be high.
Parameter 6: Light Irradiance
Light is a determining factor for primary productivity (used in photosynthesis). the removal rate of nitrogen by oysters via feeding on phytoplankton and water filtering can decline. the primary production remained at low levels (around 0.
High temperature of water (such as that of resulted from heated water) is not appropriate for the organisms’ lives. Moreover. This condition together with the low food density can lead to low biomass and even high mortalities. assimilation efficiency (the percentage of food consumed that is ultimately available to the animal for respiration and growth) decreases with increasing temperature (Malouf & Breese.003 gN/m3/d). Newell. When this condition happens in the pond. and Eble. Bacher et al.58
point for oyster such as C. When the density of phytoplankton in the pond is high due to sufficient light. virginica is 48. and appreciable death and weight loss in oysters when exposed to 410C (Kennedy.
. 1978).

and as a means of diluting and dispersing waste materials (Malouf & Breese. water flow rates need to be considered..
4. as low as 5µM. However. Higher uptake rates of seaweed require higher concentrations of nitrogen. it is also necessary to know the most appropriate water flow rates because the high rate might cause a problem for oyster growth. This is also suggested by Malouf & Breese (1978) who stated that increases in water flow rate up to some maximum failed to yield increased growth. Flowing water seems to have an important effect on oyster development.
. However.1. mentioned that the movement of water did affect the feeding and therefore presumably the growth of oysters.59
Parameter 7: Water Flow Rate
For oyster farms. as a source of oxygen and minerals. This nutrient is taken through passive diffusion and is used for its development.) Ponds
Gracilaria sp. this uptake rate will reach the maximum when the concentration of nitrogen reaches saturation.
In seawater. 2011). N is available to seaweed in three major forms: nitrate ( and urea. Low concentration of suppress the uptake of
). ammonium (
). Growth and Assimilation
. is a nutrient sink due its need to absorb nitrogen for growth.3 Parameters that Affect Nitrogen Dynamics in Seaweed (Gracilaria sp.
Parameter 1: Gracilaria sp. This is because oysters require it as food-containing medium. 1978). have been found to inhibit or even
by some seaweeds species (Abreu et al. This flow rate should be the same as those of in shrimp and seaweed ponds so that there would not be overloading water or lack of water in each pond. Malouf & Breese (1978). Coffaro & Sfriso (1997) mentioned that nitrogen limitation plays an effective role in reducing the growth rate of Gracilaria sp.

Gracilaria sp. This is the benefit of using Gracilaria sp.
.
When the condition in which nutrients are limiting. even though the thallus mass increases. Abreu et al. This
storage will be used to support its growth when dissolved nitrogen is in low concentrations. there would be declining biomass of macroalgae due to mortality as well as respiratory and exudation losses (Tyler & McGlathery. the thalli of this species can take nitrogen rapidly and store this nutrient. A simulation model from previous study suggests that during the colder month. proteins and pigments as storage compounds. 2001). et al. 2011). generally use free amino acids. 2006.. to treat effluent from shrimp farm. Assimilation rates are also proportional to the nitrogen supply. or . When the concentration of dissolved nitrogen is abundant. High density of phytoplankton might lead to a decrease in macroalga nutrient uptake and production. the uptake rates decreases with time and accumulation of nitrogen in the tissue. In addition. When the supply declines. this organism can
be a competitor for macroalgae.60
Macroalgae assimilation and growth rates depend on nutrient availability. 2006). This is supported by Brush and Nixon (2012) who mentioned that the removal of phytoplankton resulted in greatly increased macroalgal biomass.
Parameter 2: Temperature and Respiration
Temperature and respiration can affect the productivity of macroalgae. The lack of limiting nutrients such as nitrogen might result in a loss of 19-48% of production (Brush & Nixon.
Tyler & McGlathery. macroalgae use the internal storage to adapt. the assimilation rate declines. rather than small compounds such as general.. It is mentioned that the use of shrimp effluent for enrichment in place of the usual tank-fertilization would reduce the mean time in culture from 44 days to approximately 21 days (Nelson. but in
is the preferred nutrient source (Tyler & McGlathery. As phytoplankton is another sink for this nutrient. 2010.

These conditions will cause a decrease in inorganic nitrogen uptake efficiency. Higher productivity will allow the higher uptake of nitrogen and lead to nitrogen removal from water.
Parameter 4: Light Intensity
Light is a very essential parameter that affects the growth of Gracilaria sp. When the concentration of inorganic nitrogen in seaweed cells is saturated. It was observed that the maximum growth rate would occur in temperature between 200300C. 2001). the uptake during the dark periods was lower than that of when light is available (Abreu et al.61
2006). 2006)... If we compare the uptake performance of macroalgae. the nitrogen content within the detritus can be released through mineralization and can lead to an increase of inorganic nitrogen in water. For tropical species. as long as density of Gracilaria sp. there is a limit. decomposition and mineralization can increase the dissolved inorganic nitrogen concentration in water. appropriate temperature and salinity are maintained. However. favorable temperatures can support the growth of this species (Tyler & McGlathery. In warmer condition. the maximum growth rate would occur at temperature 250C (Raikar. When there is high mortality. It is important to consider self-shading and turbidity
. The decline in the productivity of red algae in low temperatures might affect nitrogen dynamics.
Parameter 3: Decomposition and Mineralization
The same as in shrimp and oyster ponds. So. However. this species can be the absorber for nitrogen through the diffusion process and reduce the final output of nitrogen. sufficient light penetration. Iima & Fujita. 2011). if these processes have high rates there could be more nitrogen accumulated in the water column. the inorganic nitrogen would not be able to diffuse to seaweed cell.

62

of water, which can affect the intensity of light in water column in order to keep the biomass and the growth rate of Gracilaria sp. high. Nelson et al. (2001) added that the nitrogen content in the thalli of macroalgae was still high when the light was limited and it was just the lower growth rate that resulted from this light deficiency.

4.2 Next Step: Testing the Possibility of Using IMTA Model to Improve Shrimp Farms

We created a conceptual model. We have all the governing equations for the model. The model would need to be completed using the software (Matlab). Once this is done, there is a need to conduct an experiment back in NTB, Indonesia.

This experiment will need to address the results of using IMTA and monoculture for shrimp farms. For example, in IMTA systems there will be three different ponds for shrimps and biofilters, whereas for monoculture system, there will be three different ponds (the same total size as IMTA ponds) only for the shrimp. The parameters that would be controlled, such as water flow rate, density of shrimp (in every pond, except in biofilters ponds), water exchange, feeding rate, pond depth, water temperature and salinity, would be maintained the same in both systems.

Doing this might be helpful in assessing which system which would be more effective to be used, in terms of the increased amount of crop productions lower cost, lower pollution (nitrogen), higher revenue, lower water pumping cost, and higher efficiency of feed utilization.

Then, the result of measuring the important parameters in the IMTA system would be used to adjust the mechanistic model so that the model would be representative for NTB shrimp farms. This flexible model could be a powerful tool in providing information about the final output of

63

nitrogen in an IMTA system. To do this, a group of scientists (able to operate this model) and a consultant (for farmers) could come to these farmers and discuss their plan.

The mechanistic model could be used to predict density of species, pond depth etc. For example, if farmers want to change some parameters such as the density of the species (shrimp, oyster, and seaweed) in the ponds or the pond depth, or how often the water in the ponds is changed etc., the scientists and consultant could do a simulation for the farmers and show how all of parameters affect the final output of nitrogen. From this simulation, the scientists could determine the best density of species, the best pond depth, and the best water exchange that allows the farms to produce the least concentration of nitrogen.

This model could also be used to predict how much cost will be expended and revenue earned by the farmers through knowing the most appropriate density of shrimp, oyster, and seaweed that should be grown in the ponds in order to get the maximum production and revenue without ignoring marine and coastal ecosystem health.

4.3 Next Step: Conduct an Experiment to Adjust the Mechanistic Model to Realistic Conditions in NTB

For further study, I want to conduct an experiment for IMTA using shrimp (Penaeus monodon), oysters (Crasssostrea sp.), and seaweed (Graciliaria) in NTB, Indonesia, in the same physical conditions and time period. Data that would be collected from this experiment would be used to test the mechanistic model and to adjust the mechanistic models that would be created.

The experiment would be using three land-based ponds like the IMTA system design. These ponds would have the same depth. The water inside each pond (pulled from seawater) would

64

have the same retention times, same flow rates, and water exchange. There would be two growing periods for the shrimp, one growing period for oysters, and three growing periods for the seaweed within a year. Water from shrimp ponds would be channeled to oyster pond, and water from oyster ponds would be channeled to seaweed ponds with specific retention times. All physical parameters would be maintained the same, whereas chemical parameters, including nutrient concentration, would be measured periodically in each pond. Besides monitoring of nitrogen concentration in each pond, the input and final output of nitrogen contained in water from this system also would be measured. For the nitrogen system, there would be measurements for the most relevant parameters that significantly affect the final output of nitrogen. These parameters might be shrimp feeding rate, shrimp growth, oyster growth, seaweed growth, mortality rate, sedimentation and remineralization rates, concentration of TAN in water column, flow rate, and water exchange.

These are important to do in order to get ideal and consistent biological, physical, and chemical parameters put into the governing equations. All these data then would be processed using the same software to produce a model for the IMTA system. If all these steps could be done appropriately, we would be able to get a more reliable approximation of nitrogen dynamics in IMTA system. In addition, it would be better to add other nutrients into the model, such as phosphorous, because nutrients other than nitrogen are important in describing ecosystem health.

then it could be a way to pursue EBM goals. government has signed NTB as one of Minapolitan areas. which is an agribusiness development based on fisheries development. If IMTA increases efficiency of feed utilization (because the excess of nutrient (nitrogen) unused by shrimps could be a source of nutrient for the biofilters). but also to provide more revenue to shrimp farmers through selling the oysters and seaweed (biofilters). and reduces the cost for seawater pumping for different ponds (through recirculating water).
In EBM framework. However. This is good news for shrimp farmers because they will be aided by the government to improve shrimp production. and reduces the waste water treatment (because this job is taken by the biofilters). In IMTA. shrimp farmers need to start considering IMTA as a solution. 2009). McLeod and Leslie. but marine ecosystem sustainability also should be maintained so that shrimp farmers and other coastal communities can get long-term benefit from the marine ecosystem. the principle is relatively simple in which people place other
. diminishing the capacity of ecosystem services (Kildow and Mcllgorn. the development of this program could create a new problem because extensive coastal and ocean economic activities could lead to vulnerability of marine and coastal areas. biofilters should be used to filter waste produced in shrimp farms and they can be placed in or near the ponds. “How might someone do IMTA in shrimp ponds and would it do what is promised?” IMTA is not a hard concept to implement. It is clear that coastal economic development is the dominant focus of government.65
In 2012. 2008. Both of these species have marketable values and the government is trying to increase the production of these species in NTB to fulfill domestic and international market needs.
IMTA shows a potential not only to maintain marine ecosystem health.

Shimoda et al. Third. some scientists such as Tendencia (2007). Using both of them will maximize the amount of waste removal. This is because each organism has different filtering targets. Pantjara et al. Pantjara (2010). (2010) also proves that low productivity in shrimp ponds can be improved using seaweed as biofilter.
First. there are some important points that need attention first. using seaweed and oysters together will give a better result than using only seaweed or vice versa. oysters. (2011) have proven that oysters have the ability to reduce excessive nutrients and other waste in shrimp ponds.
Another consideration is biofilter placement and scale of shrimp farms. For NTB. This can be applied for traditional or small scale aquaculture practices because it does not really need more space and is not that
. (1) biofilters need to decrease run off and (2) the biofilters must have a market value. Second. and there are some facts that support this idea. However. This suggests that shrimp farmers can earn more revenue through harvesting seaweed and oysters as by products or secondary crops. and both seaweed and oysters are fishery products that are commonly exported to other countries. Placing seaweed and oysters near or in aquaculture ponds can improve the development of these organisms through using excessive nutrient for their own growth. and seaweeds) that are commonly used in many countries and they improve the main cultivated organism’s growth.
There are some biofilters (such as mussels. There are two ways to place biofilters. (2006) and MacDonald et al. In addition.66
organisms in or near their shrimp ponds. First is within the same ponds (as shrimp). oysters are one of the favorite domestic and exported seafoods. I would suggest for shrimp farmers to use oysters and seaweed.

Additional revenue earned could cover construction cost and increase profits.67
costly.
A different way would be to build new ponds for each biofilter. The ponds can be arranged in tiered and circulated systems in which shrimp ponds can be the first stage. Both methods could increase the cost and require more workers. also increase (about $181. but connect each pond (the concept shown in Figure 3. However.. 2010) proved that IMTA gives higher estimated profit than monoculture due to faster growth of biofilters. In addition. oyster excretion would increase the concentration of nitrogen output.. Moreover.000 per anuum). it is anticipated that the additional revenue generated might cover the cost to build this system.2). The total
.
Other places have found this to be true. This is helpful for large-scale practices. the Minapolitan program conducted by the government could facilitate the realization of IMTA if shrimp farmers propose it to the government. placing the seaweed at the last order will cause less nitrogen output to be released to the sea. followed by oyster ponds and seaweed ponds. shrimp farmers still need to pay attention to the number of organisms placed in the same ponds so that they do not disturb each other. The water from shrimp pond will be channeled to the oyster pond. if oysters are in the last pond. but the savings from faster growth of crop. and an increase in the workforce might be needed for harvesting three species at different times.000 per anuum) (Nobre et al. This will allow seaweed to have less competitors and a higher growth rate.1 and 3. 2010). and energy savings (recirculation of seawater used).000-$599. and water from oyster pond will be channeled to the seaweed pond.000-$43. a study in South Africa (Nobre et al. For example. The use of IMTA concept might cost more up front (increase about $33. This is an appropriate design because the nitrogen and phytoplankton from the shrimp pond will be filtered first by oysters before it goes to seaweed pond. Whereas. However. energy saving etc.

695. Decentralization of governance could allow the local government to regulate this program by adjusting it with local condition and main fisheries commodities of the area. and coastal communities. but also for helping NTB government to reduce the number of unemployed people. 2012.491.. However. and for maintaining our marine ecosystem. Every province.212. 2010). 2011).
The other important thing is that IMTA could create more job opportunities.68
profits earned from monoculture and IMTA are also different.000 per year. this plan is not working well due to ineffective regulation by local government. particularly for those living in coastal areas. including NTB. and to fulfill the real needs of those who are involved in this program.
4. All these aspects suggest that implementing IMTA is not beneficial for producing more revenue for shrimp farmers. stakeholders. The Marine and Fisheries Agency of NTB has assigned 10 areas from all regencies (7 regencies) in NTB for Minapolitan development (Government of Province of Nusa Tenggara Barat. has been assigned to conduct this program.5 Recommendation for NTB Provincial Government and other related Parties related to Minapolitan
Listed below are the dimensions of this issue that relates to fisheries and could be considered by the government of NTB: 
Legal Dimension Minapolitan is confirmed by Marine and Fisheries of Republic of Indonesia through Decision Number 18. whereas profits from IMTA was about $14. This would be an opportunity for NTB.000-$15. The Marine and Fisheries
.000 per year (Nobre et al. Monoculture produced only $14.

the government could take care of these constraints and evenly distribute financial and infrastructure support.  Ecological dimension The areas assigned by Marine and Fisheries Agency of NTB are mostly areas with good conditions. Intensive aquaculture practices might not be a better choice for them because intensive aquaculture would require more capital and technical knowledge. The government needs to pay attention to this environmental change and an appropriate spatial planning in the areas chosen could help create organized Minapolitan. The use of IMTA could help prevent the threat to sustainability of marine resources. allowing these people to be able to participate in Minapolitan development.69
Affairs of Republic of Indonesia did not equip this program with a master plan and this omission often leads to failure of implementation at the local level. more than 40.000 fishers in NTB.
. Therefore. there were 112. and from this number. in 2011. Increasing the number of intensive aquaculture practices will lead to increased environmental load on the sea (this load contains excessive nutrients from feed used to grow species in aquaculture ponds) and this will inevitably perturb marine ecosystem around aquaculture area development and lead to diminishing marine ecosystem services.

Economic Dimension
According to Marine and Fisheries Agency of NTB. Therefore. The challenge for NTB will be to keep it this way.000 fishers live below poverty line (Suara NTB. 2011). the government would be advised to evaluate the regulation used to control this policy.

the government must educate people to fully understand the importance of ecosystem maintenance before implementing any ecosystem-based management approach for fisheries. but would disserve the rest who are not. Yet.

Key Players
.70

Social Dimension Coastal communities often face conflicts related to overlapping interest with others. such as scrambling fishing territories. This intensification might benefit those involved in intensive aquaculture. Furthermore. opening mangrove for developing more aquacultural ponds and subsequent waste tend to perturb ecosystems and lead to declining ecosystem service. the majority of coastal communities in this area are less educated.

Cultural Dimension Most of the coastal communities in NTB are traditional fishers and they have traditional knowledge. important to find an effective way to introduce any changes that will be made in a way to conserve and utilize traditional knowledge while recognizing that it is their cultural property. Introducing an intensive program like Minapolitan (focused on improvement of economy by using a modern tools and strategies) might benefit people’s lives but it might not be smoothly accepted. therefore. For example. they will have alternative livelihoods. For those who get involved in this program. Therefore. It is. the rest will be struggling to survive. Developing intensive aquaculture as a part of Minapolitan will be an alternative for them. a fact that could lead to conflict within coastal communities.

The periodic monitoring would also allow the government to measure and evaluate the progress of minapolitan development and the effectiveness of IMTA. This process needs the participation of coastal communities to prevent future conflict and to create an organized minapolitan. This condition tends to produce conflict due to misunderstanding and overlapping interests. in order to support Minapolitan development and implementation of IMTA to achieve the goals of developing marine and coastal economy. By doing this activity before the minapolitan is developed. particularly for intensive aquaculture areas. 2. This policy is taken as an action to improve coastal economy. there is a lack of coastal communities’ involvement (such as fishers.71
Key players in Minapolitan are national and NTB/local governments. Create a master plan of Minapolitan and include an IMTA system inside it. aquaculture. Although it seems to be accepted by coastal communities. Moreover. there is no specific local body that helps stakeholders to convey their aspiration. the following is ten recommendations for the government:
1. This is important in order to prevent social jealousy among coastal communities. and the public in general). and no periodic evaluation by local government to address this issue.
Therefore. Distribute and accommodate facilities evenly that are needed by coastal communities to participate in Minapolitan and implement of IMTA. which is in decline. 3. Monitor the standard of living periodically of coastal communities. the government can determine the benchmark for the success of economic improvement.
.

It would be effective for the government to conduct seminars or training about IMTA and invite some
. education is one of the solutions. In order for shrimp farmers to understand more about this IMTA and how IMTA can contribute to minapolitan development. This part can include the establishment of standards (ie. this funding did not go to the right people and led to a failure of the program. economic. 5. These regulations should have a part aimed to control environment maintenance. and the requirement of environmental impact assessments for the shrimp farms at least every year. Educate and train coastal communities focused on environmental. The implementation of minapolitan is predicted to increase the production of main marine commodities of NTB. nitrogen) allowed to be discarded to the sea). Improve management of financial support. not simply economic improvement. 6. due to low quality of management. Often.72
4. and institutional aspects. This is a key that should get more attention from the government. These ideas are expected to support IMTA implementation and to help government to control aquaculture practices and to keep marine ecosystem healthy. would be a problem for the farmers and coastal communities. The government should be ready for this situation because the increase in production. the government allocates funding for coastal communities. Monitor marine and coastal ecosystem conditions periodically in order to understand the changes of this ecosystem over time. 7. but.e. Develop and expand the market for aquaculture commodities. which is not followed by a similar increase in potential market. The government also needs to review all points in Minapolitan regulation. maximum pollution (i.

its implementation might not work well. Involve social and environmental scientists. but also social and environmental aspects. 10. 8. Poster presentations and advertisements might also be an interesting and understandable way to disperse this information. It is expected that this activity can change the mindset of all relevant parties such as shrimp farmers and coastal communities from “money” orientation to “money and environment” orientation. It is important to include different parties in this activity so that many issues related to their interest could be addressed and the best solution to improve management system could be pursued.73
experts in this field. If one of these aspects is ignored. These local bodies would be a medium for the farmers and coastal communities to convey their thoughts and to participate in controlling program. For example. and to produce the most effective solutions. the public. using easy or common words and explaining economic benefits yielded from IMTA and minapolitan might be effective if the audiences are coastal communities. Periodically evaluate current policy by including the stakeholders. and the bodies created to address current issues and conflicts.
. The important thing that needs to be considered is the way to convey the information about IMTA and minapolitan. 9. and related agencies in order to address better ways or strategies to maintain the environment without sacrificing social and economic aspects. Create and empower local bodies that take care of issues that emerge in each area assigned. This is because Minapolitan is not only about economic aspect. economists.

One potential solution for this situation would be to put the biofilters and shrimp in the same pond.
2. Sacrificing mangrove forests creates a new problem in the future since mangrove forests play such an important function in marine and coastal ecosystem. Difference in affordability of domestic and export markets: are shrimp consumers willing to pay more for a “green” shrimp
..
1. the effectiveness of this strategy has not been addressed because it is not known how biofilters placements within the shrimp ponds might affect the development of shrimp. Reduced mangrove forest
More ponds implies more mangroves will be cut. The solution would be to place the biofilters and shrimp in the same pond. There is a need to specifically study this issue. However. Listed below is an initial list and some possible solutions. shrimp farmers will need to consider the cost.
3.6 Potential Challenges of Implementation of IMTA
There are some challenges in implementing IMTA in Indonesia. In addition. there is a need to assess for return on investment and a need to know how long it would take for the shrimp farmers using IMTA to get the capital invested back. and Gracilaria sp.74
4. Increased cost of building more ponds
In order to build two other ponds for Crassostrea sp. but the effectiveness is still questioned.

This is supported by Richards (2012). Many people who have been aware of the importance of keeping the environment might prefer “green shrimp” rather than “non-green shrimp”. In Indonesia. Indonesia. This might make them ignore the threat on their livelihoods because of marine ecosystem degradation.
4. who stated that a real challenge for Indonesia is to produce green products for export markets and to make the products affordable for the country’s majority low-income population.75
“Green” or environmentally friendly shrimp. produced in IMTA might cost more. Lack of understanding about the negative impact of shrimp farms on marine environment
This is the biggest challenge to implement IMTA in NTB. selling this more expensive “green shrimp” might not be promising because economic problems make price the first thing (before environment) considered by most of domestic consumers. However. this might work in developed countries wherein the awareness and value about environment are high.
. Shrimp farmers tend to care a lot about revenue. Not having an understanding about the importance of reducing pollution in marine ecosystems will lead to their reluctance in getting involved.

with the mechanistic model using nitrogen as a currency built into this project. This model could help them to decide the best way to improve shrimp production while maintaining marine ecosystem. and environment maintenance) are good reasons to test this concept. Indonesia. The thing that government. This might increase environmental challenges/problems. and coastal communities need to remember is that the degradation of marine ecosystem caused by
. IMTA might help to reduce these problems. and increasing water quality. in the receiving body of water (seawater). The seawater then must absorb the excess nitrogen in the water.
The results of this project could be used to test the potential benefits of IMTA in improving shrimp aquaculture practices and the implementation of Minapolitan development. All predicted benefits (such as more revenue earned by shrimp farmers through selling the biofilters.
This project provided some recommendations for the government to control this practice so that IMTA concept offered can work effectively. could be a powerful tool used to help government and shrimp farmers avoid negative impacts on the environment that may emerge from intensification of shrimp farms. Improving shrimp farms could contribute to the increase of total fisheries production and provide an important livelihood for people living around coastal areas. IMTA using seaweed (Gracilaria sp.76
CONCLUSION Minapolitan calls to expand aquaculture. shrimp farmers. such as nitrogen. in NTB.) and oysters (Crassostrea sp.
IMTA.) as biofilters for shrimp farms might be a solution for dealing with (i) the declining shrimp production (low water quality in the pond and subsequent disease) and (ii) environmental problems caused by accumulated nutrients. Biofilters (oysters and seaweed) instead use these nutrients for their growth. increasing job opportunities.

77
shrimp farms will directly threaten other coastal community’s main livelihoods (such as capture fishing) and sustainability of the ecosystem serves not only the short term.
. This suggests that IMTA implementation needs an engagement of all relevant and impacted parties in order to make this ecosystem-based management approach to work effectively. but also in the long term interests of the region.